Aviation Week then goes techie and explains what we can see from that picture: "Photos disseminated via the European PressPhoto agency and attributed to an anonymous stringer show that the helicopter’s tail features stealth-configured shapes on the boom and the tail rotor hub fairings, swept stabilizers and a 'dishpan' cover over a five-or-six-blade tail rotor. It has a silver-loaded infrared suppression finish similar to that seen on V-22s."

Low radar visibility was essential, for the Pakistani air force would have either scrambled its jets if an unknown threat to its airspace (and near the country's best military academy!) was detected, or fired its surface to air missiles. It's possibly more proof of the fact that Pakistan really knew nothing about the mission - or at least its first wave of attack - until it ended.

More: http://news.yahoo.com/s/time/20110504/us_time/httpnewsfeedtimecom20110504couldthebinladenraidhaverevealedasecretnewhelicopterxidrssfullnationyahoo